Assessing groundwater quality and its sustainability in Joypurhat district of Bangladesh using GIS and multivariate statistical approaches

Sustainable groundwater quality is a key global concern and has become a major issue of disquiets in most parts of the world including Bangladesh. Hence, the assessment of groundwater quality is an important study to ensure its sustainability for various uses. In this study, a combination of multivariate statistics, geographical information system (GIS) and geochemical approaches was employed to evaluate the groundwater quality and its sustainability in Joypurhat district of Bangladesh. The results showed that the groundwater samples are mainly Ca–Mg–HCO₃ type. Principal component analysis (PCA) results revealed that geogenic sources (rock weathering and cation exchange) followed by anthropogenic activities (domestic sewage and agro-chemicals) were the major factors governing the groundwater quality of the study area. Furthermore, the results of PCA are validated using the cluster analysis and correlation matrix analysis. Based on the groundwater quality index (GWQI), it is found that all the groundwater samples belong to excellent to good water quality domains for human consumption, although iron, fluoride and iodide contaminated to the groundwater, which do not pose any significant health hazard according to World Health Organization’s and Bangladesh’s guideline values. The results of irrigation water quality index including sodium adsorption ratio (SAR), permeability index and sodium percentage (Na %) suggested that most of the groundwater samples are good quality water for agricultural uses. The spatial distribution of the measured values of GWQI, SAR, Fe (iron), EC (electrical conductivity) and TH (total hardness) were spatially mapped using the GIS tool in the study area.     

Environmental forensic investigation of the air pollution from a cement manufacturing unit

Abstract

Cement manufacturing is a process that results in the emission of significant quantities of suspended particulate matter (SPM) to the ambient air. An environmental forensic investigation was carried out in the surroundings of a major cement manufacturing unit at a place called Coimbatore in the southern Indian state of Tamil Nadu. The investigation was carried out to identify the contribution of the cement manufacturing unit to the SPM concentration of the surrounding air environment. The sampling points’ selection and sample collection were done following the principles outlined in the INTERPOL Manual for Pollution Crime Forensic Investigation. On-site monitoring of the air samples was carried out using Mini Laser Aerosol Spectrometer (GRIMM, Mini-LAS Model 11R). The instrument was capable of measuring particles ranging from 0.25 to 32 µm and classifying them into 31 size channels. The test results at majority of the monitoring locations were well above the limits specified in the National Ambient Air Quality Standards of India. Microscopic studies of the dust samples were carried out for surface texture and particle shape. The spatial distribution of particles was analysed using geographic information system (GIS) for the visual identification of the extent of the pollution by keeping the cement factory as the focal point. The results from the GIS and microscopic analysis established the role of the cement factory in the particulate matter pollution of its surroundings, specifically in the areas North-West of the factory. The successfully adopted procedure can serve as a guideline for the environmental forensic investigation of similar pollution incidences.     

CFD Investigation of Particle Deposition in a Horizontal Looped Turbulent Pipe Flow

This paper presents comprehensive 3D numerical investigations on depositions of particles flowing through a horizontal pipe loop consisting of four bends. The multiphase mixture model available in FLUENT 6.2 was used in this study. In this numerical simulation, five different particle sizes have been used as secondary phases to calculate real multiphase effect in which inter-particle interaction has been considered. The deposition of particles along the periphery of the pipe wall was investigated as a function of particle size and fluid velocity. The simulations showed that near the upstream of the bends, maximum particle concentration occurred at the bottom of the pipe. However, downstream the bends, the maximum particle concentration occurred at an angle of 60° from the bottom. The larger particles clearly showed deposition near the bottom wall except downstream. As expected, the smaller particles showed less tendency of deposition and lesser at higher velocity. This numerical investigation showed qualitative agreement with the experiments conducted by Commonwealth Scientific and Industrial Research Organisation, Melbourne team for similar conditions.     

Trilemma association of energy consumption,carbon emission,and economic growth of BRICS and OECD regions: quantile regression estimation

Environmental Science and Pollution Research - Recent research has shown a huge impact of non-renewable energy (NRE) production on environmental health. In this context, this work analyzes the...     

Extended Analytical Turbulent Diffusion Model for Particle Dispersion and Deposition in a Horizontal Pipe: Comparison with CFD Simulation

A 2D analytical turbulent diffusion model for particle dispersion and deposition at different heights along the pipe flow and circumferential deposition has been developed. This liquid–solid turbulent diffusion model presented in this paper has emanated from an existing gas–liquid turbulent diffusion model. This model can be used as a handy tool for quick estimation one and two-dimensional deposition fluxes of particles in water distribution networks. A comprehensive 3D numerical investigation has been carried out using multiphase mixture model available in “Fluent 6.2” to verify the above analytical model. Different particles sizes and densities were used for 3D numerical investigations. The deposition was studied as a function of particle diameter, density, and fluid velocity. The deposition of particles, along the periphery of the pipe wall and at different depths, was investigated. Both the models findings matched with qualitative phenomena such as deposition of heavier particles at the bottom of the pipe wall were higher at lower velocities and lower at higher velocities. The lighter particles were found mostly suspended with homogeneous distribution. Smaller particles were also suspended with marginal higher concentration near the bottom of the pipe wall. This marginal higher concentration of the smaller particles was found to be slightly pronounced for lower velocity. These analogies of particles are well discussed with the ratio between free-flight velocity and the gravitational settling velocity. Extended analytical model results were compared with the 3D computational fluid dynamics simulation results. Discrepancies in the model results were discussed.     

Improving pedestrian safety using combined HOG and Haar partial detection in mobile systems

Objective: The objective of this study is to develop a novel algorithm on a mobile system that can warn drivers about the possibility of a collision with a pedestrian. The constraints of the algorithm are near-real-time detection speed and a good detection rate.

Method: Histogram of gradients (HOG)-based detection is widely used in pedestrian safety applications; however, it has low detection speed for real-time systems. Hence, it has no direct usage for mobile systems. In order to achieve near-real-time detection speed, partial Haar transform predetections are applied to an image before HOG detection. The partial and HOG detections are merged and a score-based confidence level is defined for the final detection phase. In this way, the outcome is prioritized and different warning levels can be issued to warn the driver before a possible pedestrian collision.

Results: The proposed algorithm provides an increase in detection speed (from 46 to 76 fps) and detection rate (from 80 to 91%) with respect to HOG-based pedestrian detection. It also improves confidence of the results by multidetection merging and score assignment to detections.

Conclusions: Performance improvement of the algorithm is compared with respect to state-of-the-art detectors/algorithms. Based on the detection rate and detection speed performance, it can be concluded that the proposed algorithm is suitable to be used for mobile systems to warn drivers about the possibility of collision with a pedestrian.     

Analysis of Meteorological Drought Pattern During Different Climatic and Cropping Seasons in Bangladesh

Drought is one of the most frequent natural disasters in Bangladesh which severely affect agro‐based economy and people's livelihood in almost every year. Characterization of droughts in a systematic way is therefore critical in order to take necessary actions toward drought mitigation and sustainable development. In this study, standardized precipitation index is used to understand the spatial distribution of meteorological droughts during various climatic seasons such as premonsoon, monsoon, and winter seasons as well as cropping seasons such as Pre‐Kharif (March‐May), Kharif (May‐October), and Rabi (December‐February). Rainfall data collected from 29 rainfall gauge stations located in different parts of the country were used for a period of 50 years (1961‐2010). The study reveals that the spatial characteristics of droughts vary widely according to season. Premonsoon droughts are more frequent in the northwest, monsoon droughts mainly occur in the west and northwest, winter droughts in the west, and the Rabi and Kharif droughts are more frequent in the north and northwest of Bangladesh. It is expected that the findings of the study will support drought monitoring and mitigation activities in Bangladesh.     

Impact assessment of subsurface drainage on waterlogged and saline lands

Waterlogging and salinity due to seepage from canals have polluted land and environment in various parts of Pakistan. A sustainable environment requires urgent remedial measures for this problem. The research in this paper presents the impacts of the Fourth Drainage Project, Faisalabad on the twin problem of waterlogging and salinity. Monitoring of the project was made on regular basis. The key performance indicators for the project include the lowering of water table, improvement of water quality and soil salinity, increase in area under cultivation, cropping intensity, and socioeconomic status of the project population. Data regarding water levels and discharge from the drain pipes were collected to monitor the impact on waterlogging. Soil samples were tested to evaluate the impact of drainage on land. It has been found that the percentage of the contaminated land in the project area has considerably been decreased, while the cropping intensities have been increased.     

The nexus between eco-friendly technology and environmental degradation in India: Does the N or inverted N-shape load capacity curve(LCC) hypothesis hold?

This study aims to investigate the impact of eco-friendly technology on environmental degradation indicated using the load capacity factor (LCF) with the framework of the Load Capacity Curve (LCC) hypothesis. In this regard, an environmental degradation function is formed and analyzed using the Augmented Autoregressive Distributed Lag (AARDL) approach during the period spanning from 1975 to 2021 for India. The outcome indicates that eco-friendly technology reduces the LCF, thereby fostering environmental degradation in the long run, but the relationship is not significant in the short run. Further, an N-shaped LCC hypothesis has been observed in both long and short runs. Besides, energy consumption exhibits a LCF reducing or environmental degradation boosting role in the short run and long run. These findings are consistent with other models that are used to check the robustness of AARDL-based results. Thus, the study recommends policies for promoting eco-friendly technology, judicious economic growth, and cautious energy consumption to attain sustainable development by increasing the LCF in India.     

Environmental Kuznets Curve: the case of Bangladesh for waste emission and suspended particulate matter

Economists have shown the empirical relationships between the economic growth of a nation and its environmental quality using the hypothesis of the Environmental Kuznets Curve (EKC). To understand the EKC phenomena, a study of the literature was undertaken. As waste, waste emission, and suspended particulate matter (SPM) are the active agents of environmental degradation, the study focused on those agents for EKC consideration. Through understanding the different EKC trajectories, an attempt was made to relate the economic development of Bangladesh to the EKC. It is shown that the EKCs for waste, emissions from waste, and SPM follow the conventional EKC trajectory with a turning point related to higher income per capita in most cases. The type of economic policy that Bangladesh should follow to deal with the pollutants and their sources is also shown. The study recommends creating a tunnel in the EKC to lower the turning point in Bangladesh. The study is likely to help stimulate policy development in Bangladesh.